This invention relates to rotary means equipped with a multistage fan having the excellent effect of air suction and discharge.
The origin of this invention is based on U.S. Pat. No. 4,319,408 entitled "Heating process and its apparatus in reducing air pressure within a chamber at a balanced level" which was invented by the present Applicant. Further, the Applicant has filed corresponding U.S. patent applications Ser. Nos. 329,818 now U.S. Pat. No. 4457083 and 349,064 now U.S. Pat. No. 4426793 and has so far developed various related inventions including the heating process and its apparatus in reducing or pressurizing air pressure within a chamber at a balanced level.
The aforesaid inventions comprise a rotary means for reducing or pressurizing air pressure within a chamber and a suction opening in which the rotary means is disposed, wherein a difference between the reduced or pressurized air pressure within the chamber and the air pressure outside the chamber is maintained at a balanced level, and air friction heat is generated in a gap between the suction opening and the rotary means by rotation thereof, thereby the chamber can be used for drying or heating purposes.
That is to say, means for suctioning and discharging air within the chamber as well as means for generating air friction heat is formed by the rotary means having the suction opening, so that the drying or heating effect is greatly dependent upon whether or not the operational efficiency of the rotary means is high. From this point of view, this invention has been accomplished.